Coaxial cable connector



Oct. 21, 1969 F. P. CEFARELLI ETAL 3,474,385

COAXIAL CABLE CONNECTOR Filed June 8, 196'? 2' Sheets-Sheet 1 NVENTORSFRANK P. CEFARELLI ROBERT T. EVANS BY Wad ATTORNEY Oct. 21, 1969 F. P.CEFARELLI ET AL 3,474,385

' COAXIAL CABLE CONNECTOR 2 Sheets-Sheet Filed June 8, 1967 3,474,385COAXIAL CABLE CONNECTOR Frank P. Cefarelii and Robert T. Evans,Poughkeepsie, N.Y., assignors to International Business MachinesCorporation, Armonk, N.Y., a corporation of New York Filed June 8, 1967,Ser. No. 644,677 lint. Q]. Htllr 25/02 US. Cl. 339-47 6 Claims ABSTRACTOF THE DISCLOSURE This connector for a coaxial cable is comprised of anovel cable-connection section and a novel contact section providingmatched impedance. The cable-connection section includes an axialconductor having a solder slot for receiving the stripped centerconductor of the cable and a cylindrical conductor means having openingsfor soldering to the stripped shield of the cable. Heat efiectssimultaneous soldering. The cylindrical conductor means has a firstsupport extension and a second extension with two arms adapted to wraparound the support extension and the outer insulation jacket of thecable. The axial conductor is mounted in a plastic insulator ofrectangular cross section. The cylindrical means is a projection of arectangular-cross-sectioned body of the connector. The end of theconnector opposite the cable end includes an axial, projecting contactembedded in an extension of the plastic insulator and a leaf contactextending from the connector body. Both contacts have roundedformations. This connector is mounted in an insulating housing by meansof tabs and an edge and can mate with a corresponding connector so thatdual contacts are made for the signal conductor and for the groundshield of the coaxial cable. The leaf contacts provide the normal forcefor proper engagement of the axial contacts.

This invention relates to electrical connectors and more particularly toa coaxial cable connector.

In the past, it was customary in production to terminate a coaxial cable'with crimping. This was used with alternating male and feamle contactswhich required appreciable space. Further, the crimping gave bulky,irregularly shaped barrel structure. Both the double contacts and thecrimping mitigated against impedance matching. Another disadvantage ofavailable coaxial connectors was that the connetcors were screw machinedor otherwise made in a realtive expensive manner. Also, known miniaturecoaxial connectors often were not hermaphroditic so that there could bemating between connectors.

An object of the invention is the proivsion of an improved coaxialconnector which avoids the above-noted disadvantages and has uniquesolder cable connection means.

Another object is to provide a coaxial cable connector having animproved contact section comprised of an axial contact and finger-like,leaf-spring shield contact which goves proper engagement of the axialcontact.

A further object is the provision of such a connector which ishermaphroditic and thus can be mated 'with an identical connector whichis inverted.

An additional object is to provide a matched impedance coaxial connectorhaivng an inexpensive sheet body part which is combined with an axialcontact and an insulator to give improved connection to the coaxialcable and further having improved shield and center wire contacts.

In accordance with the disclosed embodiment of the invention, aconnector has an axial conductor for connection to the center conductorof a coaxial cable. The axial conductor is partially encased by adielectric which, in

nited States Patent 3,474,385 Patented Get. 21, 1969 turn, is partiallyencased by the body part of a shield connector. The axial conductor ismounted in the dielectrio with an exposed contact surface in thedielectric extension. The shield connector has a projecting curved leafcontact over the axial contact. Both contacts have rounded segments forengagement of contact sections of an identical connector. The springleaf contact assures proper engagement by the axial contact. The shieldconnector has means for electrical connection to the cable ground shieldand for mechanical wrap-around connection over the cable outerinsulation. Electrical connection is provided by cylindrical structurehaving openings and by inserting into the cylindrical structure thesolder-tinned woven wire shield of the coaxial cable. The center wire ofthe cable is received in a center solder slot of the axial conductor ofthe connector. Heating effects soldering at both locations. The shieldconnector has a tab, a projecting edge and a latch tab for positioningin a connector housing. This connector is dimensioned to give impedanceand is hermaphroditic since it mates with an identical invertedconnector.

The realization of the above objects, along with the features andadvantages of the invention, will be apparent from the followingdescription and the accompanying drawings in which:

FIG. 1 is a perspective view of the connector and coaxial cable which isstripped and arranged to be guided into the connector for soldering;

FIG. 2 is a top view of the connector and shows the axial conductor indashed lines;

FIG. 3 is a partially cross-sectioned side view and shows the latchingtab received in a recess in a connector housing;

FIG. 4 is a cross section along the line 4-4 of FIG. 3 and shows theexposed surface of the axial conductor and the reception of the guideedge in housing; and

FIG. 5 is a partial cross-sectioned side view of two mated connectorsand shows the dual point contact of both conductors of the connector.

In FIGS. 1 and 2, the coaxial connector 11 is shown with a strippedcoaxial cable 13 which is aligned for insertion into the connector. Thecoaxial cable is comprised of a center round-metal wire conductor 15, aprimary tubular dielectric or insulator 17, a woven-metal-wire shield 19and an outer insulating jacket 21. The inner or primary insulation, theshield and the outer insulation are suitably stripped dimensionallylengthwise to expose the respective part which was covered.

The outer part of connector 11 is formed from sheet metal and has arectangular body section 25, two inwardly inclined support arms 26 and27 which form two windows (one window 29 showing) and terminate ascylindrical structure 31. The upper and lower arcuate sections 33, 35have ports 37 and are separated by slits 38 (one appearing). Thispermits adjustment so that differently diametered cable shields can beguided and received. The top arcuate section 33 extends to formV-shaped, cable-gripping fingers 41, 42 which are to be bent to engagethe arcuate support extension 43 from section 35 and cable sides. Thesefingers 41, 42 accommodate differently-diametered cables. Thisarrangement of fingers and the support extension provides protectionagainst tensile and bending stresses on the cable. The ports 37 providefor applying soldering heat and inspection.

The connector body 25 encases a plastic insulator 45 which, in turn,encases the cable end of an axial rectangular conductor 47. Thisconductor has a cylindrical slot 49 at one end for receiving cablecenter Wire 15. The slot 49 is provided with solder for binding to thecable center wire 15. Conductor 47 at its other end has a reducedthickness fiat contact 51 which has a rounded cylindrical segment 53.This segment assures reliable engagement with a flat surface. Contactpart 51 is mounted in an extension 52 of insulator 45 which has aninclined ramp 54 leading to the end of contact 51 embedded in insulatorextension 52. Also at the other end of body 25, a shield leaf contact 55projects integrally and terminates in a rounded, spherical segment orcurved tip 57 having radius in two directions. The leaf contact isdownwardly inclined and then curved upwardly so that the end of thecurved tip 57 is not appreciably above the top plane of the body, whilethe bottom of the curved tip is appreciably below the top plane. (NoteFIG. 3.) The base of the leaf contact 55 is formed by slitting the topbody wall at 58 and 59. Body 25 of the one-piece outer connector partincludes a retaining or stop tab 61 and a positioning edge 63. Insulatorextension 52 is supported by extended body bottom wall 64 which forms ashield connecting contact surface.

Referring to FIG. 3, it can be seen that center conductor has beensoldered in axial slot 49 of axial pin 47 and that arcuate sections 33,35 have been soldered to the woven-metal shield 19, which was previouslytinned. Application of heat by a heated air blower, induction means orotherwise effects the solder joints which can be observed through slotsor ports 37 and windows 29. Thereafter, a clear insulating tubing 65which is made from a heat-shrinkable plastic is slipped into place tocover arms 26, 27, arcuate sections 33, 35, fingers 41, 42. Thesefingers have been bent to engage insulating jacket 21 and supportextension 43 and now, since offset, have edges closely adjacent. Thetubing 65, thus placed, is heated and shrinks to engage the mentioned,encased parts as well as the end of outer insulating jacket 21. Thistubing 65 is used when exterior insulation is required.

From FIGS. 3 and 4, it is apparent that the lateral keying edge 63,retaining stop tab 61 and latching tab 67 have been positionedrespectively in a mating groove 68 in insulating and supporting housing69, against wall 71 of housing 69 and in the recess 73 in housing 69. Arecess 75 is provided bounded by the inner surfaces of center contact51, the extended connector side walls 77 and 79, leaf contact 55 and theinsulator so that a mating center contact 51 and insulator extension 52can be inserted via ramp 54 causing flexing of leaf contacts 55 whenrounded segments 53 engage the flat sides of mating center contacts. Atthis point the spherical segments 57 of leaf contacts 55 will have asimilar point-tip engagement.

The bottom contact wall 64, insulator extension 52 and flat axialcontact can be referred to as an insulated axial-leaf contact section 81having leaf contact wall.

In FIG. 5, the above-described coaxial connector is shown mated with aninverted or oppositely-arranged corresponding connector, both mounted inhousings 69. It is to be noted that the center contact 51, insulatorextension 52 and the body contact wall 64 are received in recesses 75while leaf contacts 55 fit in recesses 73 above-mentioned. Leaf contact55 has its curved tip 57 engaging the wall of the 180 rotated body ofthe other connector and thus is slightly flexed giving reliable pointcontact. Likewise, the rounded segments 53 of axial conductors 47 areengaged with respective flat mating surfaces of the other axialconductor to give reliable point contact due to the urging of leafspring contacts. Thus, a hermaphroditic coaxial connector has beenprovided which gives dual contact for both the axial conductors 47 andthe leaf conductors 55. Dual reliability is thus achieved.

It is to be noted that keying of the connector housings causes thecontacts to mate properly. The contact of the axial members is madethrough normal forces supplied by the leaf spring contacts. The outerleaf contacts engage through spring leaf deflections along the opposingrigid box section or body. The one piece outer member provides dualshield contact, latching and keying members, cable termination, andsupport at the cable insulation. Dimensioning of parts including therectangular sections give close impedance matching. Soldering isachieved at the same time for the center conductor and shield conductor.

While the invention has been particularly shown and described withreference to a preferred embodiment thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention.

What is claimed is:

1. A connector for a coaxial cable comprised of:

an axial metal conductor having at one end an axial cylindrical slot forinsertion of the center round wire of a coaxial cable and a contact partof the other end;

a plastic insulator encasing said axial conductor except for saidcontact part;

metal shield connection means mounted on said insulator and having acontact section at one end;

said shield connection means having at its other end cylindricalstructure for the receiving of, and the bonding to, the shield of acoaxial cable;

said cylindrical structure having longitudinal slots therein forexposing the soldering of the shield of a coaxial cable;

an integral axially extending part of said cylindrical structure forreceiving a coaxial cable; and

an integral opposed support of said cylindrical structure which flaresinto a circumferential V-shape for engaging the outer insulation of acoaxial cable and the axially extending part.

2. The connector according to claim 1 and being further characterizedby:

said shield connection means having a retaining tab integral with saidother end and a projecting lengthwise orienting edge respectivelyadapted to engage the side wall and a groove of a mounting block, and

said shield connection means having a latch tab depending from said oneend for engaging a recess wall of a mounting block.

3. A connector for a coaxial cable and formed to provide electricalconnection with a similar inverted connector when in mating holderscomprised of:

an axial metal conductor having at one end an axial cylindrical slot forinsertion of the center round wire of a coaxial cable and an axialcontact part at the other end,

1 plastic insulator of square cross-section encasing said axialconductor except for said contact part under which an insulatorextension projects,

metal shield connection means mounted on said insulator and having aleaf contact section at one end projecting over said axial contact partso that a recess is formed,

said shield connection means having at its other end structure forbonding to the tubular shield of a coaxial cable,

said shield connection means having a flat engagement wall opposite saidleaf contact section so that the leaf contact section of anotherinverted connector can be engaged for connection to the shield of acoaxial cable,

said recess being formed below said leaf contact and :above said axialconductor for insertion of part of an axial conductor of anotherinverted connector, and

said leaf contact section being formed so that said axial conductor willproperly engage another axial conductor by the forces exerted by theleaf contacts.

4. A connector for a coaxial cable and formed to provide electricalconnection with a similar inverted connector when in mating holderscomprised of:

an axial metal conductor having at one end means for engaging the centerround wire of a coaxial cable and an axial contact part at the otherend,

a plastic insulator of square cross section encasing said axialconductor except for said axial contact part,

metal shield connection means having a body part mounted on saidinsulator and having a leaf contact section at one end projecting oversaid axial contact part,

an axial contact section comprising a portion of said body part, anextension of said plastic insulator and said axial contact part,

said shield connection means having at its other end cylindricalstructure for engaging the shield of a coaxial cable,

said shield connection means having a fiat engagement wall opposite saidleaf contact section so that the leaf contact section of a correspondingconnector can be engaged for connection to the shield of a coaxialcable, and

said leaf contact section and said axial contact section forming arecess which has a vertical dimension less than the axial contactsection so that spring forces are exerted when a like inverted axialcontact section is mated.

5. The connector according to claim 4 and being further characterizedby:

said shield connection means having a retaining tab integral with saidother end and adapted to engage the side wall of a mounting block,

said shield connection means having a latch tab depending from said oneend for engaging a recess wall of a mounting block, and

said shield connection means having a lateral edge for engaging a slotin a mounting block.

6. A connector for a coaxial cable and formed to provide electricalconnection with a similar inverted connector when in mating holderscomprised of:

an axial metal conductor having at one end an axial cylindrical slot forinsertion of the center round wire of a coaxial cable and an axialcontact part at the other end,

a plastic insulator of square cross-section encasing said axialconductor except for said contact part.

a one-piece, sheet metal shield connection means having a square-shapedbody part mounted on said insulator and having a leaf contact section atone end projecting over said axial contact part so that a recess isformed,

said shield connection means having at its other end cylindricalstructure for bonding to the shield of a coaxial cable,

said shield connection means having a flat engagement wall opposite saidleaf contact section so that the leaf contact section of anotherconnector can be engaged for connection to the shield of a coaxialcable,

said cylindrical structure having longitudinal slots therein forexposing the soldering to the tubular shield of a coaxial cable,

said cylindrical structure having integral support structure whichflares into circumferential fingers for engaging the opposed structureextension and the outer insulation of a coaxial cable,

said shield connection means having a retaining tab integral with saidother end and adapted to engage the side wall of a mounting block,

said shield connection means having a latch tab depending from said oneend for engaging a recess wall of a mounting block,

said shield connection means having a lateral edge for engaging a slotin a mounting block,

said axial contact part having at its end a rounded shape for reliablecontact with a corresponding contact part,

said leaf contact having a flat strip terminating in a rounded segmentat its end for point contact, and

said recess being dimensioned so that the leaf contact section willexert a force on a corresponding inserted contact section.

References Cited UNITED STATES PATENTS 453,225 6/1891 Wheeler 339-49 XR2,379,942 7/1945 Webber. 2,540,012 1/1951 Salati 339-177 XR 3,341,8019/1967 Brookman et al. 339177 XR 3,348,187 10/ 1967 Friend 339l77 XRFOREIGN PATENTS 139,466 11/ 1950 Australia.

MARVIN A. CHAMPION, Primary Examiner PATRICK A. CLIFFORD, AssistantExaminer US. Cl. X.R. 339--177 UNITED STATES PATENT OFFICE CERTIFICATEOF CORRECTION Patent No. 3,474,385 October 21, 1969 Frank P. Cefarelliet a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 4, line 14, "of", second occurrence, should read at Signed andsealed this 24th day of February 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr. E. JR.

Attesting Officer Commissioner of Patents

